Apparatus for controlling electrical circuits.



R. E. BAKER.

APPARATUS FOR CONTROLLING ELECTRICAL CIRCUITS.

APPLICATION FILED JUNEZ, 1914.

Patented Apr. 18, 1916.

3 SHEETS-SHEET I.

z J uf R. E. BAKER. I APPARATUS FOR CONTROLLING ELECTRICAL CIRCUITS.

APPLICATION FILED IUNEZ, 19I4.

1,180,103. Patented Apr. 18, 1916.

3 SHEETS-SHEET 2.

R. E. BAKER.

APPARATUS FOR CONTROLLING ELECTRICAL CIRCUITS.

APPLICATION FILED JUNE 2. 1914.

v 1 l 80, 1 ()3 Patented Apr. 18, 1916.

3 SHEETS-SHEET 3.

ZZZ/512101 UNITED STATES PATENT OFFICE.-

ROIBERT E. BAKER, 0F CLEVELAND, OHIO, ASSIGNOR TO ARTHUR G. MCKEE.

APPARATUS FOR CONTROLLING ELECTRICAL CIRCUITS.

Specification of Letters Patent.

Patented Apr. 18, 1916.

Original application filed November 25, 1912, Serial No. 733,459. Divided and this application filed June 2,

To all whom it may concern Be it known that I, ROBERT E. BAKER, a citizen of the United States, resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Apparatus for Controlling Electrical Circuits, of which the following is a specification, the principle of the invention being herein explained, and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

My invention relates to apparatus for controlling electric circuits, said apparatus being particularly adaptable for use in connection with automatic regulating devices.

The object of the invention is to provide means for effecting such control economically and efliciently.

The subject-matter of this application constitutes a division of the subject-matter of my co-pending application, Serial No. 738,459, filed November 25, 1912, for apparatus for regulating the temperature of furnaces and the like.

The said invention consists of means hereinafter fully described and particularly set forth in the claims.

The annexed drawings and the following description set forth in detail certain means embodying my invention, the disclosed means, however, constituting but one of various mechanical forms in which the principle of the invention may be applied.

In said annexed drawings :Figure 1 is a diagrammatic illustration of an appara tus embodying my invention. Fig. 2 is a plan of an indicator embodied in my invention. Fig. 3 is a section of such indicator taken upon the plane indicated by line IIIIII in Fig. 2. Fig. 4 is a horizontal section of such indicator. Fig. 5 is a section of such indicator taken upon the plane indicated by line VV in Fig. 4. Fig. 6 is a perspective View of a fragmentary portion of the indicator.' Fig. 7 is a perspective view of one of the magnets embodied in such indicator.

The said drawings illustrate. my invention as applied to an apparatus for regulating the temperature of furnaces, crucibles or other receptacles or objects whose temperature it is desired to measure and con trol, and in addition to describing my particular invention, I will also describe in de- Serial No. 842,536.

tail the complete apparatus to which it is applied, the whole being separately claimed in my above named co-pending application. In the apparatus illustrated by the drawmgs as embodying my invention, A, Fig. 1, represents a furnace or crucible whose temperature it is desired to measure and control. Projecting into this furnace or crucible at a suitable place is an ordinary thermo-couple B connected with the galvanom- 'eter G in the usual manner, so that a varia tion of temperature in the furnace, will effect a proportional movement of the indicating pointer or needle C of the galvanometer. The latter is provided with the usual graduations c. The outer end of the needle consists of a non-magnetic material, preferably a metal such as aluminum, and, where the balance of the needle is also of aluminum or a similar conducting material, is insulated therefrom by means of suitable insulation c. This outer portion of the needle carries a small armature C which hence has a path of movement defined by the arc of a circle, as will be readily understood.

Adjacent to the armatures path of movement and having their end faces parallel with such path, are the cores d d and d of three magnets D D and D respectively.

The coils of these magnets are connected in,

series in an electrical circuit E containing a battery E, Fig. 1. In the specific form of device illustrated, the faces of the cores d (Z are made equal in length and each of such faces is made of suitably greater length than the face of the core d, the latter being equally spaced laterally from said first named two core-faces, as shown in Fig. 2. Each of these three magnets is mounted upon a segmental bar F, Fig. 4., which itself is provided with a multiplicity of spaced guiding lugs f, Fig. 6, which travel in a segmental groove 9, Figs. 1 and 5, formed in the frame of the. galvanometer. The magnet D is removably secured to the bar or carrier F by means of a suitable screw f, Fig. 3, passing through a circular aperture 7, Fig. 6, located between two of the guiding lugs 7, whereby it is seen that the magnet may be readily removed and replaced by a second magnet- Laterally of said aperture f and also located between adjacent lugs f are elongated slots f through which pass screws 7" securing magnets D D to said bar. By means of these elongated slots it will be seen that the position of these last two named magnets may be adjusted longitudinally of the bar, with reference to each other and to the central or intermediate magnet ment being limited by the length of the elongated openings or slots f as will be readily understood. The fastening screws all are threaded into the inner end of the cores of the magnets'as shown, and such inner ends are formed with segmental grooves d Fig. 7, which engage a segmental tongue Fig. 5, by means of which construction it will be seen that the magnets may be accurately positioned as well as retained upon the carrier or bar F.

The bar or carrier F is retained in position by means of suitable brackets Figs.

0', 4t and 5, which engage one edge thereof,

and a strip 0 Fig. 5 which engages a groove' 7 formed adjacent to the other edge of the bar. The latter is furthermore formed near its outer and upper edge, with bevel-gear teeth f which are engaged by a bevel-pinion suitably mounted and operable through the medium of a thumb-wheel 0 projecting from the outer portion of the galvanometer s casing. It will therefore be seen that by turning the thumb-wheel 0 the carrier F together with all of the magnets may be simultaneously shifted in a direction par allel with the path of movement of the small armature C The magnetic field which is set up by these magnets is therefore intersected by the path of movement of said armature, and is also shiftable in the direction of movement of the latter.

Suitably mounted and fixed -to the galvanometers casing is a segmental contact strip H having its upper or contact surface parallel with the path of movement of the outer end of the galvanometer needle and placed in a position such that the movement of the armature 0 toward any one of the magnet cores, will effect contact between the outer end of the needle and such surface. This contact strip is of a length suffrcicnt to effect such contact in all positions into which the carrier F and magnets mounted thereon may be shifted.

Mounted upon each of the cores (Z (Z of magnets D D, is a contact strip H H, having an outer segmental contact surface e e-extensive as to length with the outer face of the core, such surface being located in the plane of the contact surface of the strip "H. These two strips form an auxiliary, interrupted and elongated contact surface which is also capable of being engaged by the end of the needle G, when subjected to movement as a result of the attraction of the armature G Such action, it will therefore be observed, will result in the electrical connection of the continuous contact surface D, such adjust-.

to periodically and recurrently make and break same at predetermined intervals. This circuit breaker may be of any suitable construction, but as illustrated embodies a circular disk J rotated at a uniform rate of speed by any suitable mechanical or other means (not shown) and which is constantly engaged by the resilient terminal a in thecircuit E. A second resilient terminal 0 also in said circuit, lies in the path of a projection 9' formed upon the disk, the length of the engaging surface of this projection being such as to produce the required period of contact and hence of completion of the circuit E.

From the construction as thus far described it will be seen that at predetermined intervals the circuit E will be completed for a. predetermined length of time, armature C attracted and the terminal strips H andH connected, at such times when the needle is opposite the magnets D D. W'hen the needle is opposite the magnet D and the circuit E is likewise periodically completed, the armature is likewise attracted but only the contact strip H engaged. The one terminal strip ll. is connected with a circuit K, Fig. 1, including the coils of a magnet K adapted to operate a relay switch L. This circuit K also contains the battery E. The other contact strip H is connected with a circuit K including the coils of a second magnet K adapted to operate a second relay switch L. This circuit K also contains the battery E. A main feed or supply circuit M is provided and connected therewith are two parallel circuits M and M containing respectively the terminals m and m with which the relay switches L and L are normally out of en-,

gagement but are adapted to engage when the respective magnets K and K are energized. The circuit M contains the coil of a solenoid M whose core M is connected with a. rack M This rack engages a pinion M connected in any suitable manner with a valve, damper or any other device (not shown) capable of controlling the temperature of the furnace or the like, such device being, as will. be readily understood by those skilled in the art, suitably located for this purpose. The other parallel circuit M contains the coil of a second solenoid M coaxial with solenoid M and whose core M is connected to the other end of the rack M When the solenoid H is energized, the

, sired to maintain a temperature of'the furrack is drawn in one direction to operate the valve to increase the temperature of the furnace and when the solenoid M is energized, the opposite movement is effected to produce a decrease of such temperature. A suitable dash-pot P is provided in'which operates a piston P connected with the solenoid-core M through the medium of a suitable pistonrod 19. As will be understood this dash-pot is provided in orderto arrest and control the movement of the solenoid cores.

The above described device operates as follows Let it be assumed that it is de- The disk J revolving about its axis, at a given period closes the circuit E, whereby the magnets D D and D become energized, the armature C is attracted, the contact strips H and the corresponding contact strip H" are connected, thus closing the circuit K. This action energizes the magnet .K which thereupon effects the movement of its armature connected with relay switch L.

This movement brings this switch into contact with the terminal m and closes the circuits M. and M, the circuit M remaining open as a result of the non-engagement of the terminal 012/ and switch L. As a result, solenoid M is energized and the valve or other device operated to increase the temperature of the furnace. As a consequence the needle of the galvanometer advances to indicate the temperature thus produced. Successive increases of temperature are in a like manner produced-until the temperature reaches a point beyond the minimum temperature desired. When this occurs the needle reaches a position opposite the intermediate magnet D and in the subsequent closing of the circuit E becomes inoperative in so far as concerns the closing of the circuit K and hence the operation of the valve or temperature controlling device. Should now for any reason or combination of circumstances, the temperature of the furnace rise above the maximum temperature desired, the

needle reaches a position opposite the other of the magnets D. In this event the periodic closing of the circuit E closes thecircuit K causing the switch L to engage terminal m and close-the circuits M and M This results in the energizing of the solenoid M and the opposite movement of the valve or temperature controlling device, as will be readily understood. In this manner it will be seen that the temperature of the furnace may be automatically controlled so as to maintain same within certain specific and predetermined limits. If it is desired to change these limits the intermediate magnet D is removed and a magnet substituted therefor having a core of different width, the magnets D D being adjusted upon the carriage F correspondingly.

It will be readily understood that my in vention can also be applied to the control of the voltage of electric circuits, the speed of operation of machinery, the amount of light in a room, or any other thing or form of energy the quantity of which can be measured by means of an indicator of the sort described, regardless of the delicacy of 22. In apparatus for controlling electric circuits, the combination of an instrument having a movable pointer provided with an armature and capable of movement in a direction transverse with respect'to the plane of indicating movement of said pointer; means for creating a magnetic field intersected by the path of movement of said armature; and an electrical circuit having elongated terminals extending parallel with and adjacent to such path and adapted to be connected by said pointer.

In apparatus for controlling electric circuits, the combination of an instrument having a movable pointer provided with an armature and capable of movement in a direction transverse with respect to the plane of indicating movement of said pointer; means for creating amagnetic field intersected by the path of movement of said terminal members adjacent to such'path and adapted to be connected as a result of the movement of said armature due to the action thereon of the said fields magnetic lines of force.

5. In apparatus for controlling electric circuits, the combination of a movable arm provided with an armature; means for creating a magnetic field intersected by the armatures path of movement; means for shifting-such field in the direction of such movement; and an electrical circuit having terminal members adjacent to such path and adapted to be connected as a result of the movement of said armature due to the action thereon of the said fields magnetic lines or" force; said shifting means adapted also to shift said terminals in said direction.

6. In apparatus for controlling electric circuits, the combination of a movable arm provided with an armature; means for creating a magnetic field intersected by the armatures path of movement; means for shifting such field in the direction of such movement; and an electrical circuit having elongated terminal members adjacent to such path and adapted to be connected as a result of the movement of said armature due to the action thereon of the said fields magnetic lines of force; said shifting means adapted also to shift said terminals in said direction.

7 In apparatus for controlling electric circuits, the combination of a movable arm provided with an armature; means for creating a magnetic field intersected by the armatures path of movement; means for shifting such field in the direction of such movement; and an electrical circuit having elongated interrupted terminal members adjacent to such path and adapted to be connected as a result of the movement of said armature due to the action thereon of the said fields magnetic lines, of force; said shifting means adapted also to shift said terminals in said direction.

8. In apparatus for controlling electric circuits, the combination of an instrument having a vibrating pointer-arm movable in a plane parallel with the graduated dial of such instrument; a magnet-structure mounted upon the latter adjacent to the path of movement of said arm; the latter being provided with an armature movable in the mag netic field created by said. structure; and terminal strips having elongated contact surfaces parallel with such path and located opposite said arm.

9. In apparatus for controlling electric circuits, the combination of an lIlStI'llIfiEIlt having a vibrating pointer-arm movable in a plane parallel with the graduated dial of such instrument; a ma net-structure mounted upon the latter adjacent to the path of movement of said arm; the latter being provided with an armature movable in the magnetic field created by said structure; and terminal strips having interrupted elongated contact surfaces parallel with such path and located-opposite said arm.

10. In apparatus for controlling electric circuits, the combination of an instrument having a vibrating pointer-arm movable in. a plane parallel with the graduated dial of such instrument; three magnets Whose coils are connected in series and which are mounted so as to create magnetic fields intersected by the path of movement of said arm; a movable carriage upon which said magnets are mounted; and means for adjustably fixing the position of said carriage.

11. In apparatus for controlling electric circuits, the combination of an instrument having a vibrating pointer-arm movable in a plane parallel with the graduated dial of such instrument; three magnets whose coils are connected in series and which are mounted so as to create magnetic fields intersected by the path of movement of said arm; a movable carriage'upon which said magnets are mounted; and means for adjustably fixing the position of said carriage, said magnets being mounted upon said carriage so as to be adjustable with reference to each other.

Signed by me, this 29th day of May, 1914.

ROBERT E. BAKER.

Attested by:

I'IERMAN EIsnLE, D. FRIEDLING. 

